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F. l. CLARK. EXPRESSION DEVICE Eon AUTOMATIC PLAYERS.

APPLICATION FILED 0CT. I8.' 1919.

Patented July 5, 1921'.

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1 parts. This obviously--requires'the mainteof thesluggish action of the latter due to FRANKA J. or MILWAUKEE, WISCONSIN Assiaiiorrv 'ro cum PNMTI@ n ACTION'coiiIrANzorMILwAuxEn wIscoNsIN, CORPORATION or wIsooNsIN.

EXPRESSION DEVICE Fon ArrToMA'rIc PLAYERS-- i Y To all whomc't may concern:

Be it known that I, FRANK J. CLARK, acitizen of the United States, rresiding at Milwaukee, iii-the county of Milwaukee and State lof Wisconsin, have invented a certain new and useful Improvement in Expression this specification.

f sion in the player chest and the load is con.

Devices vfor -Autoinatic Players, of which the following is a full, clear, concise, and; exact description, reference being hadto the* accompanying drawings, forming a part of This invention relates -to vices for automatic players. l u

Two general methods have been adopted for controlling the expression in; pneumatic player pianos `and the like. In each instance however this is accomplished by varying the degree of tension inthe player chest so as expression deto efecta corresponding-change in the force 20r with which the lhammers are driven against.

the desired strings. Bythe lirst method theV degree of tension in the player chest is variedI by controlling kthe communication vbetween the player chest and the source ofv air tension, such as the bellows and associated nance of a maximum tension in the parts connected with the bellows,l with the'result that the bellows at all times operate under full load. By the second methodthe degree of tension in the player chest is varied by `the admissionof more orv less'V atmospheric air* thereto.y This method has its advantages over the first method in that the load upon' the bellows depends upon-the degree of tensequently reduced with any reduction in the degree of vacuumv therein. Therst method has at the present time however generally superseded the second method on account a heretoforev inability to provide a suiiiciently sensitive control for the admission of the atmospheric air. Q Y f The present invention pertains to expres'- sionI devices of the-latter type and has for a general object theprovision of an exceedingly sensitivemeans for controlling the admission of atmospheric airto the vacuum system. f

The'tension in av vacuum system of the Specification of Letters Patent. 'Application 'led October 18, 1919. Serialfvllo. 381,589..v

lPatented, lJuly 5, 1921.

character referred to dependent upon the i power delivered to the bellows and upon the energy required of the system in producing the music. -For instance, assuming that the power delivered tothe bellows is` constant,x

the tension ofthe system ordinarily varies l with the -num'berof notes that are being played. This tension,l must Vhowever be maintained 'above a definite allowed mini'-k I'num degree inorder to l tion of the player parts. Another obj ect of the invention is therefore' to provide means for accomplishing this' purpose by automatically controlling thejad-r mission of atmosphericair/to the system.y

produce vproper ac- Another object iszto provide an exceed?V ingly simple expression device for player pianos and the like. i

Othery objects and advantages will here@ inafter appear.

`One embodiment ofthe invention is 'illustrated in the accompanying drawings.

I T he viewsofthe drawings are as follows: Figure 1 is a longitudinal sectional viewV through anv expression control device, made 1n accordance with the present invention,i and-illustrating diagrammatically the mannerof `connecting the `same with a pneu matic system. f I

Fg. 2 is a sectional view of a certain valve `mechanism employed.

The embodiment of! the invention shown,l includes a vacuum chamber 10 communicat-y ing preferably witha player chest 11 of any standard or approved construction by means of a pipe 12. y The usual bellows (not shown) communicate with the player chest toeffect`rl a partial vacuum therein and consequently yin the vacuum chamber 10 due to the pipe` connection 12. y

The vacuum ychamber is provided "with an air inlet preferably constituting a singlel opening 13 through 'which atmospheric air may'enter the chamber to reduce the vacuum therein, as well as in the 'player"chest, to

any desired degree.

A valve mechanism is employed for controlling the passage of air through said? opening. VThis valve mechanism is so constructed-and arranged as to be biased tovso ward open positiondue to thetension of the i f vacuum in the vacuum chamber. In the present instance this valve mechanism inchicles a pneumatic 14; in the form of a bellows having a fixed wall 15 rigidly mounted preferably on the vacuum chamber. The movable wall 16 is interposed between the fixed wall 15 and the opening 13 and carries a valve 17 of any appropriate material such as leather or felt for covering the opening 13 when the vacuum system is at rest. A. small bleedopening 1S isprovided through the valve andmov'able wall so that a brolren communication is effected betweeirtlie pneumatic and vacuum chamber and the tension of the air in the pneumatic is consequently at all times under the influence of the air tension in the chamber. Thus it will be seen that when a partial vacuum is set up in the player chest 11 and the vacuum chamber 1 0-bythe actuation of the main pump oribellows, a corresponding reduction in air pressure -is caused in the pneumatic 14, with the result that the pneumatic -14'tends'to collapse and thus lift the valve 17 away fromthe opening 13 to permit airto enter the chamber. The greater the tension 'in the chamber 10, the further the valve 17 will be moved from the closing position.

Means is provided yfor limiting or controlling this opening or lifting movement of the valve so that very fine adjustments of-th'evalve movements may be had. For this purpose the movable wall 16 is provided with an extended arm 19 preferably of resilient material, although a rigid arm might be employed. Illhen the pneumatic system is at rest this arm assumes the vfull line position of Fig. 1 in which it projects across the several fixed stops 20, 21 and 22. As soon as a partial vacuum is created, however, in the chamber 10, the arm is'carried upwardly away from these stops by the movable wall 16 until vit engages a fixed stop 23. In this position sufiicient air is admitted through the opening 13 to reduce the tension in the chamber to such a minimum that the softest tones under normal playing conditions are produced. In order to obtain a nicely lgraduated increase intone volume, several movable stops 24, 25 and 26 are provided for selective engagement with the arm -19,`preferably at various points in the length thereof. Thus when the stop 241 is thrust against thearm 19, the arm is forced slightly-away from the fixed stop Q3 toward the fixed stop 2O and the movable wall 16 with the valve 17 is consequently brought closer to the opening 13. This effects a reduction in the amount of atmospheric air admitted to the chamber 10 with the result that a slightly greater tension is quickly set up in the chamber and the player chest 11. In the same way the movable stops `portance.

further limit the movement of the wall 16 and valve 17 from the opening 13.

When the arm 19 is made of a resilient material the arrangement of the movable stops along the length of the arm at different distances from the wall 16 is of im- Since the deflection caused in the spring is proportional to the effective length thereof-the stop 26 nearest the wall 16 has a greater limiting effect on the wall than any of the other movable stops. IVhen a rigid arm is employed, however, the 'same effect `is produced 'by 'limiting the throw of each of the movable stops.

The loudest tones are produced by moving the valve 17 against the opening 13. This maybe accomplished by providing an inlet openin@` 27 in thezpneumat-ic11to completely destroy the vacuum therein. This opening is normally covered by a suitable valve 28 movable toward'or from theopening. 'IVhen lvalve'28 is movedto'open position the'vacnum inthe pneumatic 14 is destroyed with the result. that the pneumatic is expanded and the valve 17 is forced against the opening 13.

Various meansmay be provided for actuating the various movable stopsa. land 26 or the movable valve 28. Such means may be underlthe control of the operator-or under the control of the music sheet. In the present instance however, this means includes a -plurality'of pneumatics 29, 30. 31 and 32 controlled bythe music sheet by mechanism to be later explained. `The stops 24, 25 and 26 vare preferably adjustably mounted upon the movable/walls 33, 34- and 35 of the pneumatics 29,30, and 31, respectively, while the movable valve Q8 is carried by the'movable wall 36 ofthe pneumatic Each of these pneumatics may comprise a small bellows of any standardor approved construction which when in normal panded condition retain the parts in the respective postions shown -in ythe drawings. By exhausting the air from any ofthe pneumatics 2S)7 30 or 31 'the corresponding stop'is actuated to engagethe arm 19, and by exhausting the -air from vthe pneumatic 32. the valve QS'is lifted'to open-position.

Each ofthese pneumatics is connected to a valve mechanism 37, which 'will now be described, by means of a pipe 3S. This mechanism includes a body portionhaving a central chamber 39 therein which'is inconstant communication with the vacuum svstem through a pipe elf). The pipe 38 communicates with a smallchamber 41 which may be placed in communication withthe chamber 39 through a valve port 42. The chamber l1 is provided with a second valve port 43 normally open to atmospheric pressure so that atmosphere is normally admitted to the corresponding pneumatic through the pipe 38. 'A single valve 'llis mounted upon and communicating with the adapted tolcovercit'her of the ports 42 or 43. `This valve `is controlled by a diaphragm suspended across a small chamber 46 which is connected by ya pipej47 withVA the usual tracker board 48 vover which the music sheet passes.. A'partial vacuum is normally maintained in the pipey 47 and chamber. 46 by means of the small bleed opening 49 comT municating with the exhaust chamber 39,.

"Each pipe l47 communicates with. a suitable opening 50 in the tracker" board 48 over a, which `an opening or yline of openings in the musicsheetmay pass.y When this occurs air isl admitted .to the pipe 47 and theddiaphragm chamber v46 lto p lift the diaphragm45 and movey the valvev44 to open the port 42 `andclose ytheport43Qy This places the pipe 38 in communication with the exhaust pipe "40' toiwithdraw the air .from the selected pneumatic 29, 30,31 or v32g Thiseffects the collapse .ofthe selected pneumatic andthe consequentactuation of the desired stop 24,

` 25er 26 Yofithe'valve 28 to produce the desired increase in ytone volume in thecmanner above pointedout. `After the opening or openings I,in the music sheet vhave passed over the perforationl in the tracker boardatmospheric. air is cut off from the pipe 47 and the valve mechanism, asl well as the ycollapsed pneumatic, return to their normal condition. The mechanism for maintaining a lminimum working tension in the'pneumatic system will now be described. vThis mechanism may assume various forms but in the present instance includes a pneumatic 51 preferably vacuum chamber 10 through .a Lpipe 52, so

i that the air tension in the pneumatic cortension in the systemy approaches 'an operative minimum, thestop 54 yis advanced into engagement with the arm 19 to effect a move` ment of thevalve 17 toward the opening k13.

The amount of atmospheric air,` admitted to 1 the chamber 10L is thusy reduced and the proper working tension yaccordingly maintained;` f c 'In o'rdertoy guide one inefecting or correcting the adjustments ofthe systems a,

pointer such as shown at 56 may be mounted upon the rmovable wall 53 of the pneumatic 51. ablefxed scale 57 will indicate at all times the true tension in the system.

s' soon as a partial vacuum is This pointer coperating with a suit-v Various changes may be made in the emcifically described Without departing from or sacrificing any of the advantages of the inventiondefined in the v'following claims.

1. An expression device for pneumatic players including avacuum system having an air inlet,`a valvemechanism for controlling theadmission ofair through said inlet and influenced bythetension in said system toward open, position, and stops forselectively limiting the `opening movement of said valve mechanism to any desiredv degree to vary the tension in said system. 2. An expression `device lfor4 pneumatic players including :a vacuumy system having an airinlet, anfoutwardly openingk valve cooperating with said inlet yto control the fadf mission `of atmosphericfair to said system, means actuated by the-lair ytension inkksaid system-for effecting an opening movement f betweenysaid ,valve and inlet, and means. for selectively limiting said opening movement to any desired degree to varythe tension in said system.

' .3. An' expression device for pneumatic players including a lvacuum system having anair inlet, a valve mechanism for control# ling the4 admission of air to' said system, a pneumatic influenced by thetension in said system for actuating said valve mechanism toward open position, and means for selectively-limiting.. ,the opening movementV of said valve to anydesired degree to vary the tension in said system. f l Y 4. An Lexpressioncdevice for pneumatic players including a vacuum system khaving an air inlet, afvalve cooperating with said inlet to control the admission of atmospheric air to saidsystem, apneumaticactuated by theair tenslon ,in said system for moving said valve toward open, position, and means for selectively limiting said opening move ment to any desired degreeto vary the ten-- sion in said system. c

5. An expression device for pneumatick players includingf'a vacuum system having an .air inlet, a valve coperating with said inlet to lcontrol the admission of Y atmospheric air to said system, afbellows communicatinor 'with the air tension in saidsystem for e ecting an opening movement between said valve and said inlet, vand means for varying the air tension in said bellows to control the opening movement between said valve and inlet. Y 1

l 6. Anjexpression device .for pneumatic players including-a vacuum syst-emi having an air inlet, a valve cooperating with said inletto control tlie'admissionof atmospheric air to said system, a pneumatic Jfor effecting an opening movement between said valve and said inlet, Ameans for selectively limiting the opening movement of said valve to any desired degree, and means for varying the air tension vin said pneumatic to control the opening movement of said valveand inlet. y

7. An eXpression device 'for pneumatic players including a vacuum system having an air inlet, a valve coperating with said inlet to control the admission of atmospheric air to said system, a pneumatic. in continuous but variable communication with the tension of air in saidV system `for effecting an opening movement between said. valve and said inlet', and means'for controlling the air tension in said pneumaticto control such opening movement.

8. In a device of thevcharacter described the combination of a vacuum chamber having an air inlet, a valve mechanism for controlling fthe admission of air through said inlet and influenced by the tension in said chamber toward open positiomstops for selectively limiting the openingmovementro'f said valve mechanism to any desired-degree to vary the tension in said chamber, and additional means for controlling the operation of said valve mechanism. Y

9. In a device oi the character-described the combination of a vacuum chamber yhaving an air inlet, an outwardly opening valve mechanism for controlling the admission of air through said inlet and inluencedby the tension in said chamber toward open position, and means for limiting the opening movement of said valvermechanism toV any desired degree to vary the tension in said chamber at will.

10. In a device of the character described the combination of a vacuum chamber having an air inlet, an outwardly opening valve cooperating with said inlet to control the admission of atmospheric-air to saidchamber, means actuated by the air tension -in said chamber for effecting an opening movement between said valve and inlet, and means for limiting such movement to any desired degree to vary thetension in said chamber at will. l

11. In a device of the character described the combination of a vacuum chamber having an air inlet, an outwardly opening valve cooperating with said inlet to control the admission of atmospheric air to said chamber, means actuated by the air tension in said chamber for eiiecting an opening movement between said valve and inlet, and means for controlling the operation of said valve operating means.

12. In a device of the character described the combination of a vacuum chamberhaving an air inlet, a valve coperating with said inlet to control the admission of atmospheric air to said chamber, a pneumatic connected with said valve and actuated by the air tension in said chamberfor effecting an opening movement between said valve and said inlet, and means lfor limiting the opening movement of said yvalve `to any desired degree. Y

13. In ardevice of the character described lthe combination of a vacuum chamber -havingan air inlet, a pneumatic, a valve actuated bysaid pneumatic for coperation with said inlet, a ybleedduct through said valve and communicating with said pneumatic, an arm carried by said pneumatic and movable with said valve, and means for limitingthe movement 'of said arm.

14. In a device 'of the character-described the combination of a vacuiun'chamberhaving an air inlet, a pneumatic, a valve actuatedvby saidpneumatic for-cooperation with said inlet, a bleed rduct-'through said valve and communicating with said pneumatic, and means for controlling the air tension in `said pneumatic.

l15. In a device-of the character described the combination of a vacuum chamber having an air inlet, a pneumatic, a valve actuated by said pneumatic for coperation with said inlet, a bleed duct `through said valve and communicating with said `pneumatic, an arm carried by said .pneumatic and movable with said valve, means for limiting the movement of said arm, and a valve for controlling the tension of air,.in said pneumatic.

16. In a device of the character described' the combination oi a vacuumv chamber. a valve mechanism actuated by the air tension in said chamber for admitting atmospheric air to said chamber, at least one stop for limiting the opening movement of said valve mechanism, and a pneumatic for moving said sto a.

1l?, In a device of the character described the combination of a vacuum system, valve mechanism for admitting atmospheric air to said system'to vary thetension in said s vstem, and pneumatic means controlled bythe air tension .in said systembelow a certain degreefor limiting the opening of said valve mechanism;

18. In a device of the characterdescribed the combinationof a vacuum system having an air inlet, `valve mechanism actuated by the air tension in said system to admit atmospheric air to said system, means for limiting the opening movement of said valve mechanism to. any desired degree, and additional pneumatic means controlled by the air tension in said system tor controlling said valve mechanism.

19. In a device of the character described the combinationof a vacuum system having an air inlet, valve mechanism actuated by the air tensionin said system to admit atmospheric air to said system,means for limiting the opening movement of said `valve mechanism to any desired degree, additional means controlled by the air tension in said lthe combination of 'a vacuum system having an air inlet, a valve for control-ling the adsystem for controlling said valve mechanism, and indicatin'gm'eans actuated bysaid last named means fori indicating the degree ofy system and' 'influe'nce'dl by the lair itension therein tol actuate said valve vtoward open position, and -means for controlling the openingmovement of said valve to yany desired'de'gree. Y 1 f Q 21.' In a device of the character described mission of air through saidv inlet, a'pneumatic in continuous buter-variable `communil' cation vwith said system and influenced by the air tension therein to actuate said valve toward open position, and means for controll ling the opening movementof said valve.

22. In a device of the character described the combination of a vacuum system havin kan air inlet, avalve for controlling the a mission of air through said inlet, a pneuf matic for actuating said valve and having a Yao bleed openin through which a variable communication is established with the air tension in said system,-and means for controlling the movement of saidl valve.

23. In a device of the character described the combinationofy a vacuum chamber havj ing an air inlet, a valve for controlling the admission of air through said inlet, a pneu-y matic in constant communication with said chamber for actuating said valve toward open position, and an adjustable stop ^for limiting the opening movement of said valve. f

24:. In a device of the character described the combination of wa vacuum chamber having an air inlet, a pneumatic arranged adj acent said inlet and having means for controlling the admission of air through said inlet,

a communication between said pneumatic and chamber to actuate said pneumatic by the air tension in said chamber, and means for controlling said pneumatic to control the admission of air through said inlet, Y

25. In a device of the character described the combination of a vacuum system, valve rmechanism operable to admit atmospheric air to said system to vary the tension in said system, means for controlling the opening of said valve -to .anyy desired degree to obtain the desired air tension in said system, and pneumatic means controlled by the air tension in said system for limiting the'opening of said valve mechanism to maintain the air vtension in said system above a predetermined minimum.

26. An expression device for pneumatic players including a vacuum chamber having an atmospheric air inlet, a single pneumatic having means coperating with said inlet to control the admission lof atmospheric air to said chamber, a communication between an atmosphericl airinletga single valve cooperating with said inlet to controlthe admission of atmospheric air to said chamber, a pneumatic influenced, bythe air tension in said chamber yto -move said VValve toward open'position, and Vmeans for admitting atmospheric air tojsaid pneumatic to effect a movement of said valve toward'` closed posi-f tion.

28. In a device of the character described, the combination of avacuum chamber having an atmospheric inlet, and means for controlling the admission of air vthrough said inlet comprising a pneumatic having a chamber influenced by the air tension in said first named chamber, a `valve associated with said pneumatic and inlet and inuenced by the air tension in said-first named chamber to vary the admission of air through said inlet with changes of air tension in said last named chamber, and means for modifying the air tension in said last named chain- `ber to modify the action of said valve.

29. In a device of the character described,

`the combination of a chamber having an atmospheric inlet, a pneumatic having achamber communicating with said first named chamber, a valve associated with said pneumatic and inlet and infiuenced by the air tension in said first named chamber to vary the admission of air through said inlet with changes of air tension iny said first named chamber, and means for modifying the air tension in said last named chamber to modify the action of said valve.

30. In a device of the character described, the combination of a chamber having an air port, a pneumatic having a chamber influenced by the air tension iny said first named chamber, a valve associated with said pneumatic and port and influenced by the air tension in said first named chamber to vary the flow of air through said port with changes of air tension in said first named chamber, and means-for modifying the air tension in said last named chamber to n modify the action of said valve.

31. An expression device for pneumatic I` players, comprising a chamber having a `porta pneumatichaving a chamber and a said valve is actuated in a direction contra to theflow of air through said port, and means for modifying the air tension` in said last named chamber to vary the position of said valve.

32. An expression device for pneumaticv players, comprising a` chamber having a port, a pneiunatic having a chamber communicating with said first named chamber, a valve associated with said pneumatic and ccperating with said port. to control the ow of air therethrough, said valve being arranged tomove contra to such flow of air to. increase the iiovv, and means for modifying the air tension in said last named chamber to vary the action of said valve.

33. An expression device for pneumatic players, comprising a pneumatic system having a port, a pneumatic influenced by the air tension inl said system and havingamovable Wall coperating with said port for controlling the flow. of air therethrough, said Wall: being. movable in a direction; contra to such iiow to increase-the How, and; means for modifying-,the air tension in said pneumatic` to. modify the; action ofsaid,l movable Wall.

34., An expression device for pneumatic playerscomprisingf a pneumatic system hay ing al port, a pneumatic infiuencedby the air tension in said] system and having a movablewall coperatingvvth said port for controllingthe flow of air therethrough, said` Wall being arranged to move in a direction contratosuch flow to; increase the flow, and means for controllingthe action of said movable*y Wall.

In Witnessv whereof I hereunto subscribe 

